Comparator applications

About: Comparator applications is a research topic. Over the lifetime, 2518 publications have been published within this topic receiving 26639 citations.

Signal delay generating circuit

Abstract: A signal generating circuit for generating a delayed signal in response to a pulsed timing signal with a delay time which is not substantially affected by variations in supply voltage or temperature. A voltage comparator receives a first input from a voltage division point of a voltage dividing circuit coupled across a voltage source. The other input terminal of the comparator is coupled to a RC circuit and to one terminal of a switch, the other terminal of which is connected to the voltage source. The position of the switch is determined by the output of the timing signal source. If desired, a flip-flop having its set input terminal coupled to a periodic pulse source and its reset input terminal coupled to the output of the comparator may have its complementary output used as the timing signal source to the switch, with the normal output of the flip-flop providing the delayed signal. Alternatively, a pair of comparators may be provided, each comparator comparing the RC circuit voltage to a different voltage from different points on the voltage dividing circuit, with the comparator outputs and the switching signal being combined in a logic circuit to obtain the delayed signal.

Receiver for optical digital signals having different amplitudes

Abstract: A receiver for optical digital signals which have different amplitudes which comprises a transimpedance amplifier which has a photodiode connected to its input and which produces an output that is supplied to one of the inputs of a comparator. Oppositely poled diodes are connected between the inputs of the comparator and a reference voltage is supplied to the other input of the comparator and a capacitor is connected to the other input of the comparator which together with a resistor comprises a differentiator for the output signals of the transimpedance amplifier.

Bandwidth control circuit for a phase locked loop

Abstract: OF THE DISCLOSURE Control signals for switching the bandwidth of a filter in a phase locked loop are provided by comparator circuits having time delays at their inputs that vary as a function of the magnitude of changes in the outputs from a phase comparator. These variable time delays permit the comparator circuits to produce an output having a duration of the proper length in order to permit the filter to have a large bandwidth for a long enough time to permit the phase locked loop to become locked.

Capacitive physical quantity detector

Abstract: A capacitive physical quantity detector includes: a capacitor having an electrostatic capacitance changeable with physical quantity; a converter converting a capacitance change to a voltage; and a selector having a comparator and a switching element. The converter includes a C-V converting circuit having an operational amplifier for amplifying a first signal from the capacitor, a main switch between input and output terminals of the operational amplifier, feedback capacitors and feedback switches. Each feedback switch connects a feedback capacitor to the main switch when the feedback switch is closed. The selector closes the feedback switches based on a second signal of the converter. The comparator compares the second signal with a threshold voltage. The switching element switches the feedback switches according to a third signal from the comparator to set the second signal smaller than a saturated voltage and larger than the threshold voltage.

A 0.6V, 1.3GHz dynamic comparator with cross-coupled latches

Abstract: This paper presents a sub-1V dynamic comparator with cross-coupled latches at multi-GHz operation. The low-voltage cross-coupled latches structure with a separated tail current can be used to optimize the speed and the offset in the latched stage, respectively. A high speed readout circuit is also proposed to further enhance the speed of the comparator. With BER=109, the comparator achieves 143fJ at 3.3GHz and a 0.9V supply, which decreases to only 49fJ at 1.3GHz and a 0.6V supply. Both measured results are based on the input differential voltage of only 4.2mV. The comparator is implemented in 65nm CMOS technology and the chip area of the core circuit occupies 265μm2.